Suspension device



May 11, 1943. R. IREDELL. ETAL SUSPENSION DEVICE Filed March 4, 1940 3 Sheets-Sheet l INVENTORS BY HERMAN T. KRAFT ATTORNEYS May 11, 1943. R. IREDELL El'AL SUSPENSION DEVICE Filed March 4, 19 40 3 Sheets-Sheet 2 lREDELL BY HERMAN T. KRAFT 7Z4 fl7,

NEYS

INVENTORS ROBERT ATTOR I \8 W a y Patented May 11, 1943 I Itobert Iredell and H er-rnan assignors to. The Gener pany, Al -on, Ohio,

al Tire & Rubber a corporation of Ohio Ohio, Com- T. Kraft, Akron,

. pplicationMarch 1940, Serial No. 322,056

3 iv 7 l i s. (01. 24s

This invention relates to suspension devices, andparticularl'y to elastic suspensions absorbed and damped.

Both high and low speed engines when rigidly or mount'-' ings for supporting engines so that vibration is attached to a supporting structure subject such structure to severe vibrations or oscillations;

which are objectionable because fatigue stresses are set up in the structure. structure-is an automotive vehicle, the passen- In the event thegers are rendered uncomfortable-and oftentimes irritable by the vibration of the engine. -It is,

therefore, an object of the present invention'to provide an improved mounting device for at-- taching an engine to a supportingstructure so that-the transmission of vibration and oscillation from theengine to the supporting structure is reduced to a minimum. a a

Many engines are not operated at a constant speed or torque but are frequently called upon to deliver a varying amount of power. When the operator in control of the engine causes er output to be rapidly changed or causes a rapid increase or decrease in speed of theengine, the i to severe of ltime supporting structure may-be subjected shock for relatively short intervals caused by the increased or decreased torque loads transmitted. These shocksmay cause loosening or failure of the attaching device in the case of many engines, particularly stationary engines. In the case of automobiles and airplanes these shocks are carried throughout the frame of the structure, resulting in discomfort to the passengers, as well as endangering the physical structure of the machine because of fatigue-andother stresses. Therefore, it is an object of the invention to provide a mounting device of improved character which will absorb severe shocks and loads resulting from sudden acceleration or deceleration of an engine so that sudden strains applied to the supporting structure or frame of avehicle carrying the engine are minimized.

Another object is to provide an engine mounting having improved shock and vibration absorbent characteristics without sacrificing the strength and without objectionably increasing.

the size and Weight of the mounting.

Another object is to provide an improved mounting device in which a resilientand deformable cushioning element is employed having a chamber to receive air. or other gas under pressure to assist in supporting the engine and absorbing shocks and vibrations. More specifically, the invention aims to provide a support for engines which employs a hollow annulus of rubher or the like that is secured between members attached one to the supporting structure and the other to the engine.

Another object is to provide means for mounting an engine or the like which ple in design and construction and inexpensive to manufacture, the device including features of construction which permit interchangeability of parts and facilitate assembly and disassembly for the purpose of repair or replacement. Other objects and advantages will become apparent as the description of the invention proceeds; This description is made in connection with the ac companying drawings which indicate embodiments of the invention, like parts throughout the several Views being indicated by the samenumeralsof reference. 2

Fig. 1 is a-fragmentary View of the front end of an airplane showing a modified form of resilient mounting for the engine; Y

Fig. 2 is a front elevational view of the mounting device shown in Fig. 5 and is taken substantially on the line indicated at 22 of Fig. 5;

Fig. 3 is a perspective view showing one of the annular cushions used to support the engine inthe mounting structure of resilient and elastic Fig.- 4 is an elevational'detaiL' partly in section and with parts removed, illustrating the construction of one of the mounting devices shown in Figs. 1 and 2 and enlarged with respect thereto; a 1. a

Fig. 5 is.-a sectional detail taken substantially on the line.5'5 ofFig. 4;

Fig. 6 is an elevational detail showing fled-form of bracket for attaching the device to the supporting structure of the vehicle;

Fig. 7. is I an elevational view with parts removed and partly a modihaving a ring-like attaching member be used to embrace the annulus or cushion bulkhead or fire wall of an'aircraft or other en ine; i

Fig.8 is a view, partly in section-and with parts removed, taken substantially on the line 8-8 ofFig. 7.

Generally,'the present invention comprehends is relatively sim mounting a which may gral or continuous throughout its entire circumference, or substantially so, although, if desired,

it may be made in separable parts or segments. The inner and outer members are formed with spaced confronting faces, between which is disposed a resilient and deformable cushion having a chamber, which may be annular in extent, to receive air or gas under pressure. The present invention thus incorporates a pneumatic cushion or cushions for supporting the engine which are extremely efficient in absorbing vibrations and shocks and may be adjusted through variationw in the pressure within the resilient shock absorb- I ing elements to suit the requirementsof the par-- ticular engine being supported'or to suitthepar ticular speed at which a given engine "isto"be"'- operated. Suitable means is provided for "pre' venting axial shifting movements of the resilient annulus or cushion with respect to both the'in ner and outer members of the supporting device-. This shift resisting means may takethe form of suitable interfitting configurationsof the sup-' porting members and a resilient annulus or annuluses may be adhesively secured to one or both of the supporting members. In the embodiments of the invention illustrated in the drawings, the supporting devices are shown inconnection with the mounting of a radial type engine on the body or fuselage of anairplane or other aircraft. It

is to be understood, however, thatthe same or similar mounting units maybe used for other purposes and for mounting engines of other types in aircraft, automobilesand watercraft. 1

In Figs. 1 through 6 an embodiment of the invention is illustrated inwhich individual units 30 of the suspension system are disposedwiththeir axes ina substantially common -plane,-as willlater appear. Each of the units30 is 56- cured to the fire wall or bulkhead '3 of-the aircraft structure; tend-from each of the units 30 in converging relation and are secured to a ring 33 to -whichengine 29 may be attached.- 3

The outer support member of-each -ofthe suspension units 30 may be in the form of a sub-- stantially cylindrical shell 34 (Figs. 4 and 5) at-'-:- tached by countersunk rivets 35 or otherwise to a bracket 36 of arcuate shape'whichis received" between the flanges of an-attaching element-or" clevis 31 having a threaded shank portion 38 ex- 3 tending through the bulkhead 3 and receiving"- a nut 39, by means of which the body of-the fitting may be drawn tightly against the bulkhead and thereby secured in place. Bolts 45' extend' throughthe attaching element 31' and elongated" boss 46 of the bracket 36 which is receivedby the element 31, to hold the parts together.

If desired, the shell 34 may .be formedofa strip or plate of sheet steel or aluminum alloy,. which is bent or formed'to the cylindrical shape. indicated, and provided with flanged ends-40 that may be drawn together by bolts 4|.

Received within theshell 34 and circumferen' tially embraced thereby is a resilient cushion element, indicated generally at 42, which is in the form of an annulus having a substantially cylindrical outer surface and a curved innersurface," the latter preferably having the shape of a torus. The resilient cushion element 42 may be formed of rubber of like material suitably cured or vul-- 7 canized and is provided with a circumferentially extending internal chamber 43 to receive air under pressure so that the device maybe inflated. As shown in Fig. 5, the walls of theifelement 42 may be of approximately uniform thickness so A pair -of'struts'3l and 32 ex 40 that the inside approximately parallel face of the element.

surface of the chamber 43 may the adjacent outside sur- Desirably, a multiplicity of cord layers 44 arranged in diagonal or criss-cross form are embedded in 42 and vulcanized in place so as same and strengthen the walls to air pressures in the chamber 43.

the body of the element to reinforce the withstand high The cords 44 may be placed in the deformable body by means of successive layers rubber arranged with of cord material embedded in the individual cords of successive layers extending in alternate or crisscross directions, as is the custom in the manu facture of pneumatic vehicle tires.

Extending through resilient annulus 42'is the axial opening in the an inner support member in' the form of a spool and comprising elements 41 and 48 which may be substantially identical,

havingcurved tapering outer surfaces 49 which correspond in curvatur e and contour=to the inner torus shaped surface of the cushion annulus or member *42. disposed with their sm ting relation and are The spool elements 41 and are all diameter endsin abut-- formed with aligned axial bores that receive a sleeve 50. This sleeve has an outwardly directed flange 5| atone end and it is threaded'at the opposite end toreceive a nut 52. The flange 5 I "and --nut 52 engage the ends of the spools 41 and 48 to hold the latterin end to end relation on the sleeve 50. V

A bolt 53 extends through the sleeve 50, ex tending beyond the ends of the latter to receive apertured ends 54 and 55 563011- the threaded end of head5'l thereof draws the cylin-r 32, respectively. Nut the bolt 53 and drical spool-like ends of the struts 3| and- 54 and 550i the struts tightly against the ends of thesleeve 50. Thus,- the spools 41 and 48 may oscillate or rotate slightly on thesleeve 50 whilethe-latter is held'tightly between the struts 3 l and If desired, the outwardly directed cylindrical: surface of the 'resilient cushion element 42 maybe directly engaged by the' inwardly directed 'cy-i lindricalsurfaceof the shell 34, the latter being clamped about the resilient element by the bolts; 4|, so that the frictional engagement between. the shell and the resilient'element =is sufficient to prevent endwise and rotational movement of the may to the shell 34 to positively resilient annulus in the shell. resilient annulus-42 as by vulcanization,

Furthermore, the beadhesively' secured,

prevent relative movement between these parts of the suspension unit.

i In the construction shown; a circuniferentially extendingsheet or band 58 is disposed about surface of the resilient the cylindrical outer annulus 42 andis secured thereto,- asby vulcanization." It-has been found i that relatively thin metal, such as brass, is suit-' able for the band 58 -At-one portion of the band is a radially extending rib oryfin which may; be formed by outwardly directed flanged ends 59 and 6D of the band.

Theband ends 59 and 60 maybe s'olderedor braze'd'or otherwise secured together, as by rivets 6 the flanged-ends 40 0f and are disposed between the shell 34' so as :to be".

securely clampedtherebetween by the'bolts'flwhich pass throughsuitable holes 62'formed'in the band ends 59 and 60. serve to retain the band 58'in embraced by the shell annulus '42 in position. Desirably, tapering Thus" the "bolts-4| place within and" 34 to hold the resilient shells 63 and 64, spun or otherwise formed of a relativel'ylight sheet-metal such as brass, are dis through the annulus posed within the opening 42 and with their small diameter ends in abutting relation, or substantially so, and have seating engagement with the spool or support elements 48 and 41, respectively. The shells 63 and 64 are adhesively secured to the torus shaped inwardly directed surface of the resilient annulus 42, such as by vulcanization during the curing of the annulus. Accordingly, the shells 63 and 64 may be permanently attached to the inside of the annulus while the band 58 may be permanently attached to the outwardly directed surface of the annulus. If desired, the shells 63 and 64 may be integral or they may be secured together, as by soldering or brazing, along the meeting line of their abutting ends, indicated at 65. The outer ends or edges of the shells 63 and 64 are curved away from the surface of the resilient annulus 42, as indicated at 66, so that the shells do not cut or chafe the annulus when the latter is deformed by the application of a load to the suspension device. Since the outer cylindrical band 58 and the inner tapered shells 63 and 64 are secured to the resilient annulus 42 during the curing of the latter, these thin metal parts are permanently attached to the annulus and are removable there with as a unit when the annulus is taken from the suspension unit for repair or replacement. Fillets 61 may be formed of the rubber of the annulus adjacent the curved ends 66 to further resist cutting or other injury to the annulus when the latter is deformed.

As shown in Fig. 5, ends 68 of the spool or inner members which comprise the elements 41 and 48 are disposed within the plane of the ends of the resilient annulus 42 and the outer shell 34 has substantially continuous engagement with the annulus over a greater axial length of the latter than the inner supporting element or spool. This arrangement increases the resistance of the unit to objectionable or excessive axial movement under loads and when the pneumatic cushion is deflated.

In Fig. 6 is illustrated a modified form of attaching element formed with a plate or body portion 1|, which is disposed flatwise against the bulkhead 3 and attached to the latter by means of bolts 12. A pair of spaced parallel flanges, one of which is indicated at 13, embraces the elongated boss 46 of the bracket 36 similarly to the manner in which the boss is embraced by the flanges of the attaching element 31 shown in Fig. 9. Aligned apertures 14 in the flanges 13 receive the holding bolts 45. This modified form of attaching element provides a more rigid structure and because of the spaced bolts 12 holding the same to the fire wall or bulkhead of the aircraft, rotational movement of the unit is more effectively resisted and restricted to the resilient annulus 42.

An inflating stem 15 provided with a suitable valve is attached to the annulus 42 and projects from the outer surface thereof, suitable apertures being provided through the band 58 and shell 34 to receive the stem. Accordingly, air or gas under pressure may be introduced into the chamber 43 through the stem 15 to vary the resiliency of the cushion as desired.

In Figs. 7 and 8 is illustrated a modified construction for the type of suspension unit illustrated in Figs. 1 through 6, in which the shell 34, previously described, is replaced by a pair of cylindrical shells 16 which are formed with radially disposed flanged rims 11 that are located against opposite sides of a ring 18 and secured thereto by bolts 19. The ring 18 is formed with or secured to a tangentially disposed foot or base -which is secured by bolts 8| to the bulkhead or fire wall 3 of theaircraft. Between the openings for the bolts 19 the ring 18 is hollowed out, as indicated at 82, so that the ring is approximately U-shaped in cross-section, this shape of the ring making the same lighter in weight without objectionable decrease in strength.

Cylindrical portions 83 of the pans or shells are axially aligned with one another and extend in opposite directions away from the ring 18. These cylindrical portions of the shells have inwardly directed cylindrical surfaces which frictionally engage the outwardly directed cylindrical surface of the resilient annulus 42 to resist turning of the latter within the ring 18. In the event that the thin metal band 58 is used, the ends thereof may be welded or soldered together at the surface of the annulus 42, the flanged ends 59 and 68 being omitted; or if desired, the band 58 may be in the form of a section from a seamless tube of brass or bronze. The outermost ends of the shells 16 are formed with inwardly extending flanges 84 which engage the ends of the annulus 42. The inner supporting member of the suspension unit, which comprises the spool elements 41 and 48 and their related parts, may be the same as those previously described, and the same reference numerals have been applied thereto in the modification of Figs. 7 and 8. The bolt 53 and related parts of the inner member extend through openings 85 in the ends of the shells 16, these openings being large enough to permit movement of the inner member as the resilient annulus 42 is compressed under loads.

The present invention thus provides a suspension system incorporating individual suspension units which employ resilient deformable cushion members of annular or circular form that absorb vibration and severe shocks such as are encountered in the operation of aircraft engines. In its preferred form the invention comprises deformable annuluses or cushions having circumferentially continuous chambers formed therein to receive air or gas under pressure, each cushion member being confined by inner and outer supporting members which are so interlocked with one another and about the annulus or annuluses that complete separation of the support members from one another is substantially prevented, even though the cushion member be destroyed.

An important feature of the present invention is that the design and arrangement of the resilient cushions, as well as the manner in which they are mounted between the inner and outer support members, allows the air or pneumatic pressure in the cushion chambers to be varied as desired. In case all the air pressure in the cushions is released therefrom, the suspension units are still cap-able of sustaining their normal loads without objectionable loss in vibration damping and shock absorbing characteristics' Other modes of utilizing the principles of the invention may be resorted to, changes being made, as desired, in the particular construction and arrangement of parts shown and described, it being understood that numerous modifications and alterations are contemplated and that the embodiments disclosed are given for purposes of explanation and illustration only.

What we claim is:

1. A suspension device comprising a spool, a resilient annulus on the spool and having an outwardly directed circular surface, an attaching e n i w f r n ian embraced by each of the rs a lsi..inw j k y...an mumssi l h qntmps.bi shells. 5 thggnnulus to resist axial displacement of the v. MA suspension device rompxising agspoqhs l t resilienbannuluss onflth'e ,pool and having an BQBEB'T. outwardly directed circular surface, an attaghing HERMAN KRAFT- ring embracing the annuIus about said surface, 

